1. Technical Field
The present invention relates to desensitizing toothpastes, and more particularly, to a desensitizing toothpaste that contains DP-bioglass.
2. Description of Related Art
Dentin hypersensitivity, one of common dental diseases, has a prevalence rate of about 8% to 35%. However, therapy that offers instant and lasting cure is seldom available to patients diagnosed with dentin hypersensitivity. As a result, dentin hypersensitivity is an important topic in dentistry.
FIG. 1 shows a cross-sectional view of a conventional tooth and an enlarged view of part of the surface of the tooth. As shown in FIG. 1, the tooth consists of enamel 10, dentin 20, and pulp 30, which are arranged in an inward order. Dentin 20 essentially includes hydroxyapatite and has plenty dentinal tubules 21 which connect enamel 10 and pulp 30. Pulp 30 has therein nerve 31, blood vessels, and lymphatic vessels.
The typical cause of dentin hypersensitivity is as follows: due to abrasion or erosion of enamel 10, dentin 20 is exposed to thereby allow dentinal fluid within the dentinal tubules 21 to flow inward or outward in response to a change of temperature or pH value in the oral cavity; hence, the flow of dentinal fluid indirectly activates the nerve 31 to produce a sense of pain. Therefore, after beginning to drink cold water or eat, patients with dentin hypersensitivity are likely to perceive pain, because the nerve 31 in the pulp 30 is activated.
Conventional methods of medical treatment for dentin hypersensitivity are as follows: 1. protein precipitation: a related procedure is performed to allow the fluid in the dentinal tubules to undergo protein precipitation and flow less, thereby reducing the chance of activation of nerve, but this method has a drawback, that is, the cure thus achieved does not last long; 2. inhibition of nerve activation: nerve conduction is blocked with potassium ions to thereby alleviate pain, but this method has a drawback, that is, the pain is alleviated rather than prevented; and 3. dentinal tubule occlusion: the dentinal tubules are occluded with chemicals to reduce the diameter of the dentinal tubules and close the dentinal tubules, thereby shutting out external stimuli. The aforesaid methods, coupled with simple convenient use applications, such as tooth brushing, mouth rinsing, and painting, are effective in alleviating dentin hypersensitivity. Out of the above options, toothpaste is most convenient to use and most cost-effective.
FIG. 2 shows an SEM micrograph taken of a dentin specimen after use of a conventional desensitizing toothpaste. As shown in FIG. 2, after the use of a commercially-available dentinal tubule occlusion-based desensitizing toothpaste, crystalline substances do not deposit in the dentinal tubules, and the openings of the dentinal tubules are not effectively occluded; as a result, dentin hypersensitivity remains unabated. Hence, it is imperative to provide a desensitizing toothpaste effective in effectuating deposition in the dentinal tubules and occlusion of the dentinal tubules.